Natural carbonation in a corny keg?

Since bottling has gotten old fast, I'm thinking of alternatives. Since I'm addicted to the velvety carbonation that comes from bottle conditioning, I'm wondering if I can recreate that, cask-style, in a corny keg. The question, of course, is if I can, what equipment besides the keg do I need? Will there be enough pressure to get the beer out of the keg? What are the necessary amounts of priming sugar for kegging? I'd appreciate any answers those who are wiser can provide.

You'll still need a CO2 system to keep the beer from getting flat or oxidized as you tap the beer off.

Basically you act like the corny was the bottling bucket - add in your sugar-water mixture with your beer. The only difference is you don't put it into bottles. You do need to seat the keg lid with a little co2, however.

So my question remains....You have the keg, you have the gas, and you have good clear sediment free beer...why are we adding sugar and hoping for the best?

You don't use the same amount of priming sugar as bottles - you only need about 1/3 cup for a 5 gallon keg.

I do this to reduce the frequency of having to refil my CO2 bottle since I have to wait for conditioning anyway (I don't like green beer). Why not let the yeasties do the work for free? Yes, the first draw is yeasty, but it is clear after that.

BigKahuna said:

So my question remains....You have the keg, you have the gas, and you have good clear sediment free beer...why are we adding sugar and hoping for the best?

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I can't speak for anyone else, but I naturally carbonate my kegs because I don't want to buy another tank and regulator and I don't have room my in 2 keg kegerator to force carbonate anyway. Being an apartment dweller getting another appliance for chilling and carbonating isn't feasible.

OP as others stated, you will still need CO2 in order to initially set the seal on the lid and you will need it as well to avoid oxidizing the beer once you start drinking it.

bradsul said:

I can't speak for anyone else, but I naturally carbonate my kegs because I don't want to buy another tank and regulator and I don't have room my in 2 keg kegerator to force carbonate anyway.

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Please pardon my ignorance but why would you need another CO2 tank and especially a second regulator?

Brad...Reason enough.
I'll try and shut up now.

Parva said:

Please pardon my ignorance but why would you need another CO2 tank and especially a second regulator?

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I'm assuming that he only has room in his kegerator for 2 corny kegs and his gas is inside the kegerator as well. To force carb beer at lower pressures you need to have it under pressure for days to reach the right carbonation.

Since the beer would be outside the kegerator, the pressure would need to be much higher than it would otherwise be for a cold keg. Hence a second CO2 tank and regulator.

BigKahuna said:

Brad...Reason enough.
I'll try and shut up now.

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Is that a memorable quote thread post?

I think so...

mmb said:

I'm assuming that he only has room in his kegerator for 2 corny kegs and his gas is inside the kegerator as well. To force carb beer at lower pressures you need to have it under pressure for days to reach the right carbonation.

Since the beer would be outside the kegerator, the pressure would need to be much higher than it would otherwise be for a cold keg. Hence a second CO2 tank and regulator.

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What he said.

I have my first brew (ever) carbonating in the keg right now. I used 3/8 of a cup of cane sugar instead of the 5/8 cup of cane sugar the recipe recommended for bottling. My hope is to either hit my desired carbonation or undershoot and finish off when I get it chilled and on the gas, but I had a couple of thoughts:

1. I've done a lot of searching around, but can't find this- has anybody done the math for sugar carbing in a 5 gallon corny? All I can find is varied attestations that 1/2, 2/3, and ALL of the sugar for bottling work to carb in the keg. I assume the headspace is the defining factor and that the math is relatively simple, but I'm also lazy and guessing that somebody has done this before. I'd love to make up a "natural carb in the corny" chart if there isn't one.

2. I assume that I could use a spunding valve set to the desired pressure for the volumes I want at room temperature (So higher pressure, compared to what I want when I chill it down) and that this would offer a degree of insurance compared to trying to hit my desired carbonation by measuring the sugar. I could see this being really useful if I got into krausening as well.

Just to follow up- 2 weeks with 3/8 of a cup of sugar carbonated the beer, but not much.

There's a bunch of variables, though. The keg was at cellar temperature since my headlong plunge into kegging and homebrewing has left me without the funds to complete my keezer just yet. I suspect that had I chilled the beer down, increasing its ability to absorb C02, I might have been able to get more of the naturally- produced gas into my beer.

I'm not going to mess around with my amounts just yet. I'd like to try a batch at a couple of weeks with the same amount of carbing sugar, but chill the keg down before letting off any pressure.

cedar_lake said:

Just to follow up- 2 weeks with 3/8 of a cup of sugar carbonated the beer, but not much.

There's a bunch of variables, though. The keg was at cellar temperature since my headlong plunge into kegging and homebrewing has left me without the funds to complete my keezer just yet. I suspect that had I chilled the beer down, increasing its ability to absorb C02, I might have been able to get more of the naturally- produced gas into my beer.

I'm not going to mess around with my amounts just yet. I'd like to try a batch at a couple of weeks with the same amount of carbing sugar, but chill the keg down before letting off any pressure.

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You need the keg to be warm, not cold, to get it carbonated with sugar. Unless you are using bottled CO2 in which case cold is good. I carbonate naturally often but use speise - not sure of the spelling. I hold back about 2-1/2 pints of wort and pour that in when I keg.

JMass said:

You need the keg to be warm, not cold, to get it carbonated with sugar. Unless you are using bottled CO2 in which case cold is good. I carbonate naturally often but use speise - not sure of the spelling. I hold back about 2-1/2 pints of wort and pour that in when I keg.

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Right. I had my keg in the brew closet with priming sugar for a couple of weeks, then into the 60 degree cellar and on to the gas to dispense. I ended up using C02 to make up the rest of the carbonation. I wish I could have known what pressure I had created by fermenting the priming sugar.

Warm for fermentation to happen, cold for C02 to be absorbed into the beer, yes? So if fermentation at 65 degrees produces C02, some of which is able to absorb into the beer at 65 degrees and some of which ends up sitting on top of the beer, chilling the keg ought to allow more of the C02 to get into the beer. I'm just kind of wondering how much.

It'll carb faster if you can hold it at 70 or just above. Down in the 60's and it'll carb, but it will take longer.

cedar_lake said:

Right. I had my keg in the brew closet with priming sugar for a couple of weeks, then into the 60 degree cellar and on to the gas to dispense. I ended up using C02 to make up the rest of the carbonation. I wish I could have known what pressure I had created by fermenting the priming sugar.

Warm for fermentation to happen, cold for C02 to be absorbed into the beer, yes? So if fermentation at 65 degrees produces C02, some of which is able to absorb into the beer at 65 degrees and some of which ends up sitting on top of the beer, chilling the keg ought to allow more of the C02 to get into the beer. I'm just kind of wondering how much.

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I suppose that if you hooked up your CO2 to the corny at a low pressure and then gradually increased the pressure you should be able to figure out what pressure you are at when the CO2 tank begins to hiss (or right before that point).

There is a great color chart for all normal ranges of temperature and pressure and tells you based on the style of beer what the correct pressure range should be.

Nice carb. chart. Thanks!!!

SevenFields said:

Nice carb. chart. Thanks!!!

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I have a copy of it by my keezer. It takes away a lot of the guesswork.

Hello, ive been going through the same issue. I have a two tap system and i dont want to wait for a new keg to have to force carb when i make a keg change. My problem is that everyone seems to tell you something different when you ask how much sugar to use when priming a keg. And further more there is a few flaws in calculating for the correct answers. For example, when you calculate sugar for a 5 gallon batch in bottles, the temperature variable is reletive to the temperature you fermented at and not the serving temp as is for pressurizing a keg for the temperature that it will be served at. Also, the psi measurement for kegs is based on a constant pressure of a set psi that is being maintained by adding more co2 as its absorbed by the beer where as in bottles there is a set volume of pressure created by the yeast and sugar. That being said, if priming a keg is different than bottles, then what is the equation? It cant be determined by pressure because force carbing is a different animal. And how do you compensate for the pressure required to seal the corny since it isnt a constant pressure and just is the preassure in the head space?